A study out of the University of Illinois may show that breastmilk can have a positive effect on an infant’s genetics. According to the study, when an infant is breastfed it improves the genetic ability to fight illnesses.

Previous research has shown that infants who are breastfed tend to have stronger immune systems and suffer from fewer illnesses and allergies. Until now, health professionals were not entirely certain about what caused this. This new study however may shine some light on the reason.

According to the researchers, what an infant eats early in life has some effect on the infant’s genetic expression. Healthy, nutrient dense foods, such as breastmilk, provide enough fuel for genes to synthesize a gene product and essentially “turn on”.

“Genes are really sensitive to nutrition,” said study researcher Sharon Donovan of the University of Illinois. “And we now have genes that may explain many of the clinical observations of how breast-fed and formula-fed infants differ.”

Researchers compared formula fed and breastfed infants at 3 months of age, looking at how their genes were were expressed. They found at least 146 genetic differences between the two groups of infants, many of them that affect the immune system and the development of the intestines. Some of the genes affected were those that offered protections against “leaky gut”, a condition where food and other particles can enter the bloodstream through the intestinal wall. When this happens, it leads to an increased risk of allergies and inflammatory diseases.

What an infant eats, whether formula or breastmilk, can affect the genes in two ways. The factors for decoding the individual genes can be affected, or the gene itself can be manipulated into refolding its shape. The later may be permanent, which could explain the lifetime benefits that breastfeeding brings.

“Breastmilk evolved to feed human infants, and it contains a number of bioactive elements,” Donovan said, such as hormones, growth factors and plentiful fibers.

“Cow’s milk (the primary ingredient in formula) evolved to feed calves,” Donovan continued. Its composition is much different than human milk, and its bioactive elements are often destroyed during processing, she said.

Of course, manufacturers are continuously trying to tweak formula to make it more like breast milk. “But even though people have been breastfeeding infants for thousands of years,” Donovan said, “we [scientists] still have a lot to learn.”

The study was partially funded by Mead Johnson, a maker of infant formulas. Despite this, breastmilk was still shown to be healthier for infants. – Summer, staff writer